An elevator installation is often configured to display location information for one or more elevator cars (e.g., which floor or floors the elevator cars are currently at or near). Such information is traditionally provided by an elevator control unit in the installation, the control unit being generally responsible for handling operations like moving the elevator cars in response to elevator calls. If, for example, a multiple-elevator system is being modernized, a modernization elevator control unit may need car position information for a non-modernized elevator car. However, sometimes the location information is not available or is not easily available from an elevator control unit. During a modernization, it may be difficult for a modernized elevator control unit to obtain location information from a non-modernized elevator control unit.